Continuous wave and active Q-switched operation of Watt-level LED-pumped two-rod Nd,Ce:YAG laser

A high-performance LED-side-pumped two-rod Nd,Ce:YAG laser with continuous-wave(CW) and acousto–optical(A-O) Q-switched operation is demonstrated in this work. A symmetrically shaped flat–flat cavity with two identical LEDside-pumped laser modules is employed for power scalability. In the CW regime, the maximum output average power of laser at 1064 nm is 4.41 W, corresponding to a maximum optical conversion efficiency of 5.3% and a slope efficiency is 12.4%. In the active Q-switched regime, the pulse energy of laser reaches as high as 0.89 m J at a repetition rate of 800 Hz with a pulse width of 457.2 ns, the corresponding highest peak output power is 1.94 k W and the M~2 factor is measured to be about 8.8. To the best of the authors' knowledge, this is the first demonstration and the highest performance of a CW LED-side-pumped two-rod laser Nd,Ce:YAG with Watt-level output reported so far.

Clinical analysis of 114 cases of bronchiolitis in infants

BACKGROUND Bronchiolitis is a common lower respiratory tract infection in infants and young children.Severe cases may be accompanied by obvious dyspnea and oxygen saturation decline.AIM To summarize the clinical features,standard diagnosis,and treatment of bronchi-olitis.METHODS This is a retrospective analysis of 114 pediatric patients(74 males,40 females)who were first diagnosed as having bronchioles at the Department of Pediatrics of Tongling Maternal and Child Health Hospital from January 2019 to December 2019.The clinical features,imaging features,treatment,and other clinical data were recorded and analyzed.RESULTS The age of onset of the disease was mainly from 1 mo to 6 mo(75.4%),and the time to hospital visit was mostly from the 2nd day to the 4th day of the course of the disease(75.4%).Lung imaging examination showed increase in lung texture,fuzzy(93.8%).The main treatment was atomization therapy:Budesonide combined with terbutaline(45.6%)and budesonide combined with salbutamol(38.5%).The average hospitalization time was 7.1±2.4 d,and the overall cure rate was 94.7%.In patients without bacterial infection,the use of antibiotics significantly prolonged the length of hospital stay(7.8±2.5 d vs 5.7±1.8 d)and improved the cure rate(98.3%vs 87.9%,P<0.05).CONCLUSION Infants with bronchiolitis are mainly male and tend to have a good prognosis.However,the unneeded use of antibiotics may prolong the length of hospital stay significantly,which imposes the burden both on the patients and hospital system.CONCLUSION Bronchiolitis is a common acute respiratory infectious disease in infants and young children.It mainly affects male children and the age onset is between 1 to 6 mo.The standard use of antibiotics should be emphasized in view of the prolonged average length of hospital stay between the antibiotic treatment group and the non-antibiotic treatment group.When the course of disease is more than 7 d or the treatment effect is poor,active anti-infective treatment is needed to improve the long-term prognosis.Very few children have recurrent cough and wheezing symptoms within 1 year,which may be related to the risk of later asthma attack.FOOTNOTES Author contributions:Shi C and Wu MH contributed to study conception and design,and provision of study materials or patients;Shi C contributed to administrative support;Zuo A,Yang MM,and Jiang RR contributed to data collection and assembly;Shi C contributed to data analysis and interpretation,and manuscript writing;all authors contributed to the final approval of the manuscript.Institutional review board statement:The study was conducted in accordance with the Declaration of Helsinki(as revised in 2013).The study was approved by Institutional Review Board of Tongling Maternal and Child Health Hospital.

A local refinement purely meshless scheme for time fractional nonlinear Schrodinger equation in irregular geometry region

A local refinement hybrid scheme(LRCSPH-FDM)is proposed to solve the two-dimensional(2D)time fractional nonlinear Schrodinger equation(TF-NLSE)in regularly or irregularly shaped domains,and extends the scheme to predict the quantum mechanical properties governed by the time fractional Gross-Pitaevskii equation(TF-GPE)with the rotating Bose-Einstein condensate.It is the first application of the purely meshless method to the TF-NLSE to the author’s knowledge.The proposed LRCSPH-FDM(which is based on a local refinement corrected SPH method combined with FDM)is derived by using the finite difference scheme(FDM)to discretize the Caputo TF term,followed by using a corrected smoothed particle hydrodynamics(CSPH)scheme continuously without using the kernel derivative to approximate the spatial derivatives.Meanwhile,the local refinement technique is adopted to reduce the numerical error.In numerical simulations,the complex irregular geometry is considered to show the flexibility of the purely meshless particle method and its advantages over the grid-based method.The numerical convergence rate and merits of the proposed LRCSPH-FDM are illustrated by solving several 1D/2D(where 1D stands for one-dimensional)analytical TF-NLSEs in a rectangular region(with regular or irregular particle distribution)or in a region with irregular geometry.The proposed method is then used to predict the complex nonlinear dynamic characters of 2D TF-NLSE/TF-GPE in a complex irregular domain,and the results from the posed method are compared with those from the FDM.All the numerical results show that the present method has a good accuracy and flexible application capacity for the TF-NLSE/GPE in regions of a complex shape.